Power line communication (PLC), also called mains communication, power line transmission (PLT), broadband power line (BPL), power band or power line networking (PLN), is a term describing a method for using power distribution wires for simultaneous distribution of data. A carrier can communicate voice and data by superimposing an analogue signal over standard 50 Hz or 60 Hz alternating current (AC). For indoor applications PLC equipment can use household electrical power wiring as a transmission medium.
Power line communication (PLC) might have interferences to fixed radio broadcasting or other external transmissions. Today, PLC modems or PLC devices have fixed notch filters for amateur radio bands. Filters for fixed notches can be implemented with a high suppression and very steep slopes.
Concepts of dynamic or smart notching enables PLC modems to detect an ingress of fixed radio broadcast stations in the short wave frequency range between 3 MHz and 30 Mhz. The publication ETSI TS 105 578; Power line Telecommunications; “Coexistence between PLT modems and short wave radio broadcasting services”; ETSI 2008 describes an adaptive frequency notching technique, which on the one hand has a minimum impact on data throughput and QoS (Quality of Service) requirements and, on the other hand refuses interference between PLT (Power line telecommunications) and short wave radio broadcast.
Today, PLC modems use the frequency range above 30 MHz only with a very limited power spectral density (PSD). However, in order to achieve higher data rates or coverage, it is envisaged to enable higher feeding limits for PLC in those frequencies. Then there is a high potential to observe interferences from PLC to frequency modulated (FM) radio broadcast.
There is a need to improve the prior art power line communication modems and systems in order to reduce influence on signals transmitted and received in frequency ranges above 30 MHz.